Shoulder straps are fitted on many items in order to make it easier to carry them. Such items are e.g. musical instruments, backpacks, golf bags, child carriers, laptop computer cases, attaché cases, handbags etc. Shoulder straps are also fitted on brassieres and in this case carry the weight of a woman's breasts. Traditional shoulder straps transfer a stress to a user's shoulder and neck area, e.g. the trapezius muscle. Prolonged exposure to a heavy weight via a shoulder strap often leads to pain and fatigue and can eventually lead to headache, injury and neck problem.
One way of reducing this problem is to equip the shoulder strap with a cushioning pad of a soft material. Such a pad distributes the weight from the strap over a larger area, thus reducing the pressure, but the downward force on the upper part of the shoulder area is not reduced.
A typical example of a shoulder pad for a guitar strap is disclosed in U.S. Pat. No. 6,481,022 to D'Addorio et al. This pad is configured to better distribute the weight of a carried item, such as a guitar, over a larger area. However, the weight is still supported by the upper part of the shoulder. Other devices, such as shoulder harnesses, are designed to shift some of the load to straps or belts that encircle the chest or the waist, but this will lead to restricted breathing and/or chafing of the hip and waist area.
Carry golf bags are today often equipped with two shoulder straps, and the bag is carried as a backpack. The use of two shoulder straps balances the weight evenly on the body and also distributes the downwardly directed force to two straps. The straps are equipped with cushioning material for reducing the contact pressure, but the weight is taken up by the upper part of the trapezius muscle and collarbone.
Laptop computer cases are today often equipped with one shoulder strap, and the bag is carried on one shoulder with the shoulder strap either diagonally over the body or straight on one side of the body. The strap is typically equipped with cushioning material for reducing the contact pressure, but the weight is also here taken up by the upper part of the trapezius muscle and the collarbone.